1. Field of the Invention
The invention relates generally to cutting tools; and more particularly to a cutting tool made of ceramic material.
2. Description of Related Art
Conventional cutting tools are generally made of metallic materials. These cutting tools are used for machining hard metallic materials such as cast iron, steel, and the like. When a typical cutting tool performs repeated cutting, the temperature of the cutting tool increases, and this results in reduced hardness of the cutting tool. The cutting tool generally has poor heat resistance and poor resistance to wear, and is liable to become blunt over time. This reduces the cutting tool's effectiveness, and leads to inconsistent and unwanted cutting results.
In order to circumvent the above-mentioned disadvantages, ceramic materials have been used to make cutting tools. Ceramics possess extremely high hardness, and excellent wear resistance and heat resistance. U.S. Pat. Nos. 5,382,273 and 5,525,134 respectively disclose ceramic cutting tools. Each ceramic cutting tool comprises a rake face, a flank face, and a cutting edge defined at a junction of the rake face and the flank face. The ceramic cutting tool is used for cutting metallic materials.
However, conventional ceramic cutting tools comprise only one blade. These cutting tools can cut light, thin and soft materials only at relatively low speeds. Furthermore, once the cutting edge of the blade becomes worn or is damaged, the entire cutting tool must be replaced. Moreover, ceramic materials are brittle, and the cutting tools made thereof are apt to be damaged.
A new ceramic cutting tool which overcomes the above-mentioned problems is desired.